My speculation: as Sep. 3rd, the massive military parade in Beijing draw closer, Chinese government appears to be knocking at open source developers' doors, asking for repo removal.
Sort of impossible to take a project down unless Github itself goes around and nukes each and every fork. Though it's now in a thousand different places with no clear maintainer.
This can be linked to previous takedown of shadowsocks, see this hacker news thread: https://news.ycombinator.com/item?id=10101469
Updated: and DDoS is an option too, https://news.ycombinator.com/item?id=10115513